2002 silverado 1500 4x4 w/ leaking transfer case. probably been asked, but are there any fixes, or just replace it?

 

Sounds like the dreaded "Pump Rub" you can google it and find tons of articles about it. It will cost a bunch at the dealership, but if you do a little research this is a repair you can make yourself for around $400. The Duramax guys were really some of the first to have this problem and come up with a cheap alternative. kennedydiesel.com has some kits that include the new plate and the rear housing. I haven't had the problem yet but I have bookmarked a bunch of stuff just in case. Good luck.